Shot noise
![Photon noise simulation. Number of photons per pixel increases from left to right and from upper row to bottom row.](/Images/godic/202502/05/Photon-noise5357.jpg")
![The number of photons that are collected by a given detector varies, and follows a Poisson distribution, depicted here for averages of 1, 4, and 10.](/Images/godic/202502/05/Poisson_pmf.svg5357.png")
Shot noise or Poisson noise is a type of electronic noise which can be modeled by a Poisson process. In electronics shot noise originates from the discrete nature of electric charge. Shot noise also occurs in photon counting in optical devices, where shot noise is associated with the particle nature of light.